Wireless power transferring method and device therefor

ABSTRACT

A method for receiving, by a power receiver, wireless power from a power transmitter. The method includes a ping phase of detecting execution of digital ping of the power transmitter and transmitting a response to the detected digital ping to the power transmitter using a first communication protocol; and a configuration phase of transmitting a configuration packet to the power transmitter using the first communication protocol, wherein the configuration packet includes communication protocol information of the power receiver indicating a second communication protocol supported by the power receiver. Further, the power receiver supports the second communication protocol, based on that a value of the communication protocol information is ‘1’, and the power receiver does not support the second communication protocol, based on that the value of the communication protocol information is ‘0’.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.16/349,914 filed on May 14, 2019, which is the National Phase of PCTInternational Application No. PCT/KR2017/012737, filed on Nov. 10, 2017,which claims priority under 35 U.S.C. 119(e) to U.S. ProvisionalApplication Nos. 62/422,567, filed on Nov. 15, 2016, 62/538,790, filedon Jul. 30, 2017, and 62/540,052, filed on Aug. 1, 2017, all of whichare hereby expressly incorporated by reference into the presentapplication.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a wireless power transferring methodand a device therefor.

Discussion of the Related Art

A contactless wireless charging method is an energy transfer method forelectromagnetically transferring energy without using a wire in a methodfor transmiting energy through an existing wire so that the energy isused as power for an electronic device. The contactless wirelesstransmission method includes an electromagnetic induction method and aresonant method. In the electromagnetic induction method, a powertransmission unit generates a magnetic field through a powertransmission coil (i.e., a primary coil), and a power reception coil(i.e., a secondary coil) is placed at the location where an electriccurrent may be induced so that power is transferred. In the resonantmethod, energy is transmitted using a resonant phenomenon between thetransmission coil and the reception coil. In this case, a system isconfigured so that the primary coil and the secondary coil have the sameresonant frequency, and resonant mode energy coupling between thetransmission and reception coils is used.

SUMMARY OF THE INVENTION

This specification newly defines a profile concept, that is, anindex/criterion for a compatibility determination, in order to identifya power transmitter and a power receiver in which compatibility ismutually maintained.

Furthermore, this specification proposes a communication protocol/methodselection method for stably maintaining communication compatibilitybetween a power transmitter and a power receiver having the sameprofile, but having different power classes.

In accordance with an embodiment of the present invention, a wirelesspower transfer method of a power transmitter may include a selectionphase of monitoring the placement and removal of an object for aninterface surface of the power transmitter, a ping phase of receiving aresponse from a power receiver by performing digital ping using a firstcommunication protocol, an identification/configuration phase ofreceiving a configuration packet including configuration information ofthe power receiver using the first communication protocol, wherein theconfiguration packet includes power class information of the powerreceiver and communication protocol information of the power receiver, anegotiation phase of selecting any one of the first communicationprotocol and a second communication protocol different from the firstcommunication protocol based on the power class information and/or thecommunication protocol information using the first communicationprotocol, a calibration phase of improving the ability to detect aforeign object by controlling a specific parameter, and a power transferphase of performing communication with the power receiver using theselected communication protocol and transferring power to the powerreceiver.

Furthermore, the power class information may indicate a power classclassified based on a received power level of the power receiver, andthe communication protocol information may indicate a communicationprotocol supported or preferred by the power receiver.

Furthermore, the negotiation phase may include checking the power classof the power receiver based on the power class information, selectingthe first communication protocol when the power class is a power class0, and selecting the first or the second communication protocol based onthe communication protocol information of the power receiver when thepower class is a power class 1.

Furthermore, the phase of selecting the first or the secondcommunication protocol may include selecting the second communicationprotocol when the communication protocol information indicates that thepower receiver supports or prefers the second communication protocol,and selecting the first communication protocol when the communicationprotocol information indicates that the power receiver does not supportor prefer the second communication protocol.

Furthermore, the power class 0 may indicate that received power of thepower receiver is within a 5 W to 30 W range, and the power class 1 mayindicate that received power of the power receiver is within a 30 W to150 W range.

Furthermore, the first communication protocol may correspond to aninband (IB) communication protocol defined in a wireless powertransmission and reception system, and the second communication protocolmay correspond to an out-of-band (OOB) communication protocol defined ina different communication system other than the wireless powertransmission and reception system.

Furthermore, the IB communication protocol may correspond to acommunication protocol based on a load modulation and frequency shiftkeying (FSK) method, and the OOB communication protocol may correspondto a short range communication protocol.

Furthermore, when the second communication protocol is selected in thenegotiation phase and the second communication protocol corresponds toBluetooth, the negotiation phase may further include receiving, from thepower receiver, a Bluetooth medium access control (MAC) address of thepower receiver used in the Bluetooth.

Furthermore, the calibration phase may include transmitting, to thepower receiver, a connection request message including the Bluetooth MACaddress and parameters necessary to establish the Bluetooth connection.

Furthermore, the power transmitter and the power receiver may have thesame profile.

Furthermore, the compatibility of power transfer and communication ismaintained between the power transmitter and the power receiver havingthe same profile.

Furthermore, the profile of the power receiver may be indicated throughthe configuration packet.

Furthermore, the profile of the power transmitter may be indicatedthrough a capability packet including information on a power leveltransferred by the power transmitter.

Furthermore, a power transmitter includes a coil assembly configured tocomprise at least one primary coil generating a magnetic field, a powerconversion unit configured to convert electric energy into a powersignal, and a communication and control unit configured to controlcommunication and power transfer with the power receiver. The powertransmitter may be configured to monitor a placement and removal of anobject for an interface surface of the power transmitter by controllingthe coil assembly, perform digital ping through a first communicationprotocol by controlling the communication and control unit and receive aresponse from a power receiver, and receive a configuration packetincluding configuration information of the power receiver through thefirst communication protocol by controlling the communication andcontrol unit, wherein the configuration packet may include power classinformation of the power receiver and communication protocol informationof the power receiver, select any one of the first communicationprotocol and a second communication protocol different from the firstcommunication protocol based on the power class information and/or thecommunication protocol information through the first communicationprotocol by controlling the communication and control unit, improve theability to detect a foreign object by controlling a specific parameter,perform communication with the power receiver through the selectedcommunication protocol by controlling the communication and controlunit, and transfer power to the power receiver by controlling the powerconversion unit.

Furthermore, the power class information may indicate a power classclassified based on a received power level of the power receiver, andthe communication protocol information may indicate a communicationprotocol supported or preferred by the power receiver.

A conventional communication protocol/method selection method has aproblem in that communication compatibility is not stably maintainedbetween a power transmitter and power receiver having different powerclasses because a profile and/or power class is taken intoconsideration.

In contrast, the communication protocol/method selection method of thepresent invention has effects in that communication compatibility isstably maintained and an efficient communication protocol/method can beselected for each situation because a communication protocol/method isselected by taking into consideration a profile and/or power class.

In addition, various effects according to an embodiment of the presentinvention are described in detail hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an embodiment of various electronic devices intowhich a wireless charging system is introduced.

FIG. 2 illustrates a wireless power transmission/reception systemaccording to an embodiment of the present invention.

FIG. 3 is a flow diagram illustrating a power transmission/receptionmethod in an inductive mode.

FIG. 4 illustrates a power transmission control method in the inductivemode.

FIG. 5 illustrates a power transmission device according to anembodiment of the present invention.

FIG. 6 illustrates a power reception device according to an embodimentof the present invention.

FIG. 7 illustrates a frame structure for data communication during powertransmission.

FIG. 8 is a diagram illustrating a sync packet according to anembodiment of the present invention.

FIG. 9 is a diagram illustrating a power transmission method in a sharedmode.

FIG. 10 is a diagram illustrating a method for controlling a wirelesspower transmission/reception system to which FOD extension is appliedaccording to an embodiment of the present invention.

FIGS. 11 and 12 are concept views showing a WPC communication flow.

FIG. 13 is a communication flowchart according to an embodiment of thepresent invention.

FIG. 14 is a table illustrating profiles newly defined according to anembodiment of the present invention.

FIG. 15 is a diagram illustrating a configuration packet of a powerreceiver according to a first embodiment of the present invention.

FIG. 16 is a diagram illustrating a capability packet of a powertransmitter according to a first embodiment of the present invention.

FIG. 17 is a diagram illustrating a configuration packet of a powerreceiver according to a second embodiment of the present invention.

FIG. 18 is a diagram illustrating a capability packet of a powertransmitter according to a second embodiment of the present invention.

FIG. 19 is a diagram illustrating a configuration packet of a powerreceiver according to a third embodiment of the present invention.

FIG. 20 is a diagram illustrating a capability packet of a powertransmitter according to a third embodiment of the present invention.

FIG. 21 is a table illustrating preference for a communicationprotocol/method for each category according to an embodiment of thepresent invention.

FIG. 22 is a flowchart illustrating a communication protocol/methodselection method of a PCI power transmitter according to an embodimentof the present invention.

FIG. 23 illustrates a configuration packet according to an embodiment ofthe present invention.

FIG. 24 is a flowchart illustrating a communication protocol/methodselection method of a PCI power transmitter according to an embodimentof the present invention.

FIG. 25 is a diagram illustrating a Bluetooth (or BLE) medium accesscontrol (MAC) packet of a power receiver according to an embodiment ofthe present invention.

FIG. 26 illustrates a Bluetooth (or BLE) handover procedure according toan embodiment of the present invention.

FIG. 27 is a flowchart illustrating a wireless power transfer method ofa power transmitter according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Terms used in this specification are common terms which are now widelyused by taking into consideration functions in this specification, butthe terms may be changed depending on an intention of those skilled inthe art, a use practice, or the appearance of a new technology.Furthermore, in a specific case, some terms have been randomly selectedby the applicant. In this case, the meaning of a corresponding term isdescribed in a corresponding part of a corresponding embodiment.Accordingly, the terms used in this specification should not beunderstood simply based on their names but should be understood based ontheir substantial meanings and contents over this specification.

Furthermore, although embodiments of the present invention are describedin detail with reference to the accompanying drawings and contentsdescribed in the drawings, the present invention is not limited to orrestricted by the embodiments.

Hereinafter, some embodiments of the present invention are described indetail with reference to the accompanying drawings.

FIG. 1 illustrates an embodiment of various electronic devices intowhich a wireless charging system is introduced. In FIG. 1, electronicdevices are classified according to an amount of power transmitted andreceived in the wireless charging system.

Low power (approximately 5 W or less or approximately 20 W or less)wireless charging may be applied to wearable devices such as a smartclock and smart glass and mobile/portable electronic devices such as anearphone, a remote controller, a smart phone, PDA, a tablet PC, etc.Medium power (approximately 50 W or less or approximately 200 W or less)may be applied to medium and small appliances such as notebookcomputers, robot cleaners, TVs, sound devices, cleaners, monitors, andthe like. In addition, large power (approximately 2 kW or less or 22 kWor less) wireless charging may be applied to kitchen appliances such asa blender, a microwave oven, and an electric rice cooker, personalmobile devices such as a wheelchair, an electric kickboard, an electricbicycle, and an electronic device/moving means such as an electricvehicle, etc. The electronic devices/moving means illustrated in FIG. 1may include a power receiver to be described below.

Hereinafter, a low power and a mobile device will be mainly described,but this relates to an embodiment, and the wireless powertransmission/reception method according to the present invention may beapplied to various electronic devices described above.

Wireless Power Consortium (WPC) standardizes wireless powertransmission/reception related technology for standardization ofwireless power transmission/reception devices.

The recently developed wireless charging system may support low powertransmission and reception up to approximately 5 W. However, recently, asize of a mobile device becomes large and a battery capacity alsoincreases, in the case of such a low power charging system, there is aproblem in that a charging time is long and efficiency is lowered, andas a result, a wireless charging system for supporting medium powertransmission and reception of up to approximately 15 W to 20 W. At thesame time, a wireless charging system having a resonance method added tocharge a plurality of electronic devices has also been developed. Thepresent invention relates to a wireless charging system having aresonance method added and intends to propose a resonance type wirelesscharging transmitter/receiver that is compatible with alow-power/medium-power induction-type wireless chargingtransmitter/receiver.

Hereinafter, the inductive and resonant wireless charging transmitterand wireless charging receiver proposed by the present invention and acharging method and a communication protocol using the same will bedescribed. Further, hereinafter, a resonance type/mode may be referredto as a shard type/mode. In addition, hereinafter, the wireless powertransmitter may be referred to as a power transmitter or transmitter andthe wireless power receiver may be referred to as a power receiver orreceiver.

FIG. 2 illustrates a wireless power transmission/reception system 2000according to an embodiment of the present invention.

In FIG. 2, the wireless power transmission/reception system 2000includes a mobile device 2010 and a base station 2020 that receive powerwirelessly.

The mobile device 2010 includes a power receiver 2011 that receiveswireless power through a secondary coil and a load 2012 that receivesand stores the power received by the power receiver 2011 and suppliesthe received and stored power to a device. In addition, the powerreceiver 2011 may include a power pick-up unit 2013 that receives awireless electric power signal communication and converts the receivedwireless electric power signal into electric energy through thesecondary coil and a communications and control unit 2014 that controlscommunication and electric power signal transmission/reception (powertransfer/reception) with the power transmitter. The mobile device mayalso be referred to below as a power reception device.

The base station 2020 as an apparatus that provides inductive power orresonant power may include one or more power transmitters 2021 andsystem units 2024. The power transmitter 2021 may transmit theinductive/resonant power and control power transmission. The powertransmitter 2021 may include a power conversion unit 2022 that generatesa magnetic field through a primary coil(s) and converts/transmits theelectric energy into an electric power signal and a communications andcontrol unit 2023 that controls communication and power transfer withthe power receiver 2011 so as to transmit the power at an appropriatelevel. The system unit 2024 may perform other operation controls such asinput power provisioning, control of a plurality of power transmitters,and user interface control. The base station 2020 may also be referredto below as a power transmission device.

The power transmitter 2021 may control transmission power by controllingan operating point. The controlled operating point may correspond to acombination of a frequency, a duty cycle, and a voltage amplitude. Thepower transmitter 2021 may control the transmitted power by adjusting atleast one of the frequency, the duty cycle/duty ratio, and an amplitudeof input voltage. Further, the power transmitter 2021 may supplyconstant power and the power receiver 2011 may control the receivedpower by controlling a resonant frequency.

A coil or coil portion may hereinafter be referred to as a coilassembly, a coil cell, or a cell, including the coil and at least oneelement adjacent to the coil.

Inductive mode—low power and mid power

Hereinafter, a power transfer method of the power transmitter/receiveroperating in the inductive mode will be described first. However, atleast one of a method for describing the inductive mode or phasesincluded in the method may be used selectively or optionally in theresonant mode.

FIG. 3 is a flow diagram illustrating a power transmission/receptionmethod in an inductive mode.

In the wireless charging system according to the present invention, thewireless charging may be performed through five phases. The five phasesmay include a selection phase, a ping phase, an identification andconfiguration phase, a negotiation phase, and a power transfer phase andhowever, the negotiation phase may be omitted in the low power-modepower transmission/reception. That is, in the lower power mode, thepower transmission/reception may be performed by four phases and in theintermediate power mode, the negotiation phase may be additionallyperformed.

In the selection phase, the power transmitter monitors contact/departureof an object with respect to an interface surface provided in thetransmitter. As shown in FIG. 2, the wireless power transmitter maysense the contact of an external object by applying the electric powersignal. In other words, the power transmitter applies a short electricpower signal to the primary coil and senses the current of the primarycoil generated by the electric power signal to monitor the presence ofthe external object. In addition, when the power transmitter receivessignal strength information (packet) monitored in the selection phaseand detects the object based on the received signal strength information(packet), the power transmitter may select whether the object is thepower receiver or a simple external object (a key, a coin, etc.). Forsuch a selection, the power transmitter may further perform at least oneof the following phases: the ping phase, theidentification/configuration phase, and the negotiation phase.

In the ping phase, the power transmitter may perform digital ping andwait for the response of the power receiver. The digital ping representsthe application/transmission of the electric power signal to detect andidentify the power receiver. When the power transmitter finds the powerreceiver, the power transmitter may extend the digital ping to proceedto the identification/configuration phase.

In the identification/configuration phase, the power transmitter mayidentify the selected power receiver and obtain configurationinformation of the power receiver, such as a maximum power amount. Inother words, the power transmitter may receive theidentification/configuration information, obtain information on thepower receiver, and use the information to establish a power transfercontract. This power transfer contract may include constraints on aplurality of parameters that characterize power transfer in a subsequentpower transfer phase.

In the negotiation phase, the power receiver may negotiate with thepower transmitter to create an additional power transfer contract. Inother words, the power transmitter may receive a negotiation request/information from the power receiver and the negotiation phase may beperformed only if a target receiver is identified as an intermediatepower receiver in the identification/configuration phase. In thenegotiation phase, additional parameters such as the guaranteed powerlevel of the power transmitter and the maximum power of the powerreceiver may be negotiated. When the power receiver is a low-powerreceiver, the negotiation phase may be omitted and theidentification/configuration phase may directly proceed to the powertransfer phase.

In the power transfer phase, the power transmitter provides powerwirelessly to the power receiver. The power transmitter receives controldata for transmitted power to control power transfer accordingly. Inaddition, when restrictions of the parameters depending on the powertransfer contract are violated during the power transfer, the powertransmitter may stop the power transfer and proceed to the selectionphase.

FIG. 4 illustrates a power transfer control method in the inductivemode.

In FIG. 4, each of the power transmitter and the power receiver mayinclude a power conversion unit and a power pickup unit, respectively,as illustrated in FIG. 1.

In the power transfer phase of the inductive mode described above, thepower transmitter and the power receiver may control the amount of powertransferred by parallel communication with power transmission andreception. The power transmitter and the power receiver operate at aspecific control point. The control point represents a combination ofvoltage and current provided at an output of the power receiver when thepower transfer is performed.

In more detail, the power receiver selects a desired controlpoint—desired output current/voltage, a temperature of a specificlocation of the mobile device, etc., and determines an actual controlpoint which currently operates at present. The power receiver maycalculate a control error value by using the desired control point andthe actual control point and transmit the control error value as acontrol error packet to the power transmitter.

In addition, the power transmitter sets/controls a new operatingpoint—the amplitude, the frequency, and the duty cycle—by using thereceived control error packet to control the power transfer.Accordingly, the control error packet is transmitted/received at apre-configured time interval in the power transfer phase and as theembodiment, the power receiver may set and transmit a control errorvalue as a negative value in the case of intending to decrease thecurrent of the power transmitter and set and transmit the control errorvalue as a positive value in the case of intending to increase thecurrent. As described above, in the inductive mode, the power receivertransmits the control error packet to the power transmitter to controlthe power transfer.

The resonance mode to be described below may operate in a differentmanner from that in the inductive mode. In the resonant mode, one powertransmitter needs to be able to charge a plurality of power receiverssimultaneously. However, in the case of controlling the power transferas in the inductive mode described above, the power to be transferred iscontrolled by communication with one power receiver, and as a result, itmay be difficult to control the power transfer for additional powerreceivers. Therefore, in the resonant mode of the present invention, amethod is to be used, in which the power transmitter commonly transfersbasic power and the power receiver controls a resonant frequency thereofto control the amount of received power. However, the method describedin FIG. 4 is not completely excluded in the operation of the resonantmode and additional transmission power may be controlled by the methodof FIG. 4.

Shared mode (resonant mode)

FIG. 5 illustrates a power transmission device according to anembodiment of the present invention.

In FIG. 5, the power transmission device may include at least one of acover 3031 covering a coil assembly 3020, a power adapter 3070 supplyingpower to the power transmitter, a power transmitter PTx transmittingwireless power, or a user interface 3068 providing power transferprogress and other pertinent information. In particular, the userinterface 3068 may be optionally included or may be included as anotheruser interface of the power transmission device.

The power transmitter PTx may include at least one of the coil assembly3020, a tank circuit (or impedance matching circuit) 3040, an inverter3080, a communication unit 3030 or a control unit 3050.

The coil assembly 3020 includes at least one primary coil that generatesthe magnetic field and may be referred to as a coil cell.

The impedance matching circuit 3040 may provide impedance matchingbetween the inverter and the primary coil(s). The impedance matchingcircuit 3040 may cause resonance at a suitable frequency to boostprimary coil current. The impedance matching circuit 3040 in amulti-coil power transmitter may further include a multiplexer thatroutes a signal from the inverter 3080 to a subset of the primary coils.The impedance matching circuit 3040 may be referred to as a tankcircuit.

The inverter 3080 may convert a DC input signal into an AC signal. Theinverter 3080 may be driven as a half-bridge or full-bridge to produce apulse wave and the duty cycle of an adjustable frequency. Further, theinverter 3080 may include a plurality of stages so as to adjust an inputvoltage level.

The communication unit 3030 may perform communication with the powerreceiver. The power receiver performs load modulation to communicate arequest and information for the power transmitter PTx. Thus, the powertransmitter PTx may monitor an amplitude and/or a phase of currentand/or voltage of the primary coil in order to demodulate datatransmitted by the power receiver by using the communication unit 3030.Further, the power transmitter PTx may control output power to transmitdata using a frequency shift keying (FSK) method or the like through thecommunication unit 3030. To this end, a wireless charger mayadditionally include a current sensor to detect the receiver bydetecting a current change of the primary coil, and to detect thetransmitted data of the detected receiver.

The control unit 3050 may control communication and power transfer ofthe power transmitter. The control unit 3050 may control powertransmission by adjusting the operating point. The operating point maybe determined, for example, by at least one of an operating frequency,the duty cycle, and an input voltage.

The communication unit 3030 and the control unit 3050 may be provided asa separate unit/element/chipset or may be provided as oneunit/element/chipset as illustrated in FIG. 1.

Although not shown in the figure, a Radio Frequency Identification(RFID)/Near Field Communication (NFC) reader unit (or an NFC functionunit) for detecting the RFID/NFC cards may be further mounted on a powertransmitter.

FIG. 6 illustrates a power reception product or device PRP according toan embodiment of the present invention.

In FIG. 6, the power reception product or device PRP may include atleast one of a user interface 4020 that provides power transfer progressand other pertinent information, a power receiver PRx that receiveswireless power, a load circuit 4080, or a base 4010 that supports andcovers a coil assembly 4070. In particular, the user interface 4020 maybe optionally included or may be included as another user interface ofthe power reception device PRP.

The power receiver PRx may include at least one of the power converter4050, the tank circuit (or impedance matching circuit) 4060, the coilassembly 4070, the communication unit 4040, and the control unit 4030.

The power converter 4050 may convert AC power received from thesecondary coil to voltage and current suitable for the load circuit4080. As the embodiment, the power converter 4050 may include arectifier. Additionally, the power converter 4050 may adapt reflectedimpedance of the power receiver PRx.

The impedance matching (tank) circuit 4060 may provide impedancematching between a combination of the power converter 4050 and the loadcircuit 4080 and the secondary coil. As the embodiment, the impedancematching circuit 4060 may cause resonance in the vicinity of 100 kHzwhich may enhance the power transfer.

The coil assembly 4070 may include at least one secondary coil andoptically further include an element that shields a metal portion of thereceiver from the magnetic field.

The communication unit 4040 may perform load modulation forcommunication of the request and other information to the powertransmitter PTx. To this end, the power receiver PRx may switch aresistor and a capacitor so as to change reflection impedance.

The control unit 4030 may control reception power. To this end, thecontrol unit 4030 may determine/calculate a difference between an actualoperating point of the power receiver PRx and a desired operating point.In addition, the control unit 4030 may adjust/reduce the differencebetween the actual operating point and the desired operating point byrequesting adjustment of the reflection impedance of the powertransmitter PTx and/or adjustment of the operating point of the powertransmitter PTx. When the difference is minimized, optimal powerreception may be performed.

The communication unit 4040 and the control unit 4030 may be provided asa separate element/chipset or may be provided as one element/chipset asillustrated in FIG. 1.

Meanwhile, although not shown in the figure, a Radio FrequencyIdentification (RFID)/Near Field Communication (NFC) reader unit (or anNFC function unit) for detecting the RFID/NFC cards may be furthermounted on a power transmitter.

In the shared mode, the power transmitter needs to manage an exchange ofinformation with one or more power receivers. To this end, the powertransmitter provides a structure for communication with the powerreceiver and such a structure is the same as a communication framedescribed below.

In FIG. 7, the power transmitter provides a structure that provides asequence of time slots in which each power receiver may transmit datapackets. A sync pattern illustrated in FIG. 7 is provided between therespective slots. The sync pattern serves not only to separate theslots, but also to optimize the communication of the power receiver. Inparticular, the sync pattern may provide the receiver with informationfor collision resolution and guaranteed latency.

FIG. 7 illustrates a frame structure for data communication during powertransfer. A shard mode protocol may use two types of frames, i.e., aslotted frame and a free-format frame. The slotted frame may be used forthe power receiver to transmit short data packets to the powertransmitter and the free-format frame may be used for other purposessuch as bi-directional larger data packet transmission and coilselection in the multi-coil transmitter.

All frames start with the sync pattern and a measurement slot and themeasurement slot may be used to measure the transmission power and thereception power. As the embodiment, 9 slots may be included in oneslotted frame. For the free-format frame, there are no specific formatrestriction beyond the sync pattern and the measurement frame. A startbit (information) of a sync packet may indicate the start of the frame.

FIG. 8 is a diagram illustrating a sync packet according to anembodiment of the present invention.

As illustrated in FIG. 8, the sync packet may include at least one of apreamble, a start bit, a response field, a type field, an Info field,and a parity bit.

The preamble includes a sequence of bits set to one. The number of bitsinvolved may vary depending on the operating frequency. The start bitmay be set to zero. The parity bit is a last bit of the sync pattern,and may be set to 1 when the bits set to 1 included in the data fieldsincluded in the sync pattern are even and to 0 otherwise.

The response field may include a response of the transmitter tocommunication from the receiver in a preceding slot. 00 may indicatenon-acknowledge regarding that the communication may not be detected, 01may indicate not-acknowledge regarding that a communication error isdetected, and 10 may indicate not-acknowledge regarding that thecommunication is correctly received, and 11 may indicate acknowledgeregarding that the communication is correctly received.

The type field may be set to 1 for a first sync pattern included in theframe and may be set to 0 for other sync patterns.

The Info field has a different value and meaning according to the syncpattern indicated in the sync field. First, when the type field is 1,the info field may indicate whether the frame is the slotted frame orthe free-format frame. In addition, when the type field is 0, the Infofield may indicate whether a next slot is a slot allocated to a specificreceiver, a slot temporarily provided to a specific receiver, or a freeslot which may be used by any receiver.

FIG. 9 is a diagram illustrating a power transmission method in a sharedmode.

In the shared mode, the power transfer method may include a selectionphase, an introduction phase, a configuration phase, a negotiationphase, and a power transfer phase.

The selection phase may represent a selection phase in the inductivemode illustrated in FIG. 3 and in the shared mode, the selection phasemay be omitted and the remaining four phases may be described. In theshared mode, if the presence of frequency shift keying (FSK) in theelectric power signal is detected before the wake-up timeout, theprocess may proceed directly to the introduction phase.

In the introduction phase, the power receiver may request a free slot totransmit control information (CI) packets to use in the next phases. Tothis end, the receiver transmits an initial CI packet. When the powertransmitter responds with the ACK, the power receiver may proceed to theconfiguration phase. When the power transmitter responds with the NAK,another receiver may perform the configuration phase or the negotiationphase. Therefore, the receiver may request the free slot again. When thereceiver receives the ACK, the receiver may determine a private slotthereof in the frame and thereafter, transmit the CI packet b using theslot at the corresponding location.

In the configuration phase, the power transmitter may provide a seriesof locked slots for exclusive use of the power receiver. This is for thereceiver to perform the configuration phase without a collision. Thereceiver may transmit two identification data packets (IDHI and IDLO),and optionally at least one proprietary data packets, and aconfiguration packet (CFG) using the locked slots. Upon completing sucha phase, the receiver may proceed to the negotiation phase.

In the negotiation phase, the transmitter may also continuously providethe locked slots for exclusive use of the receiver. This is also for thereceiver to perform the negotiation phase without the collision. Thereceiver uses the locked slots to transmit negotiation data packets(including a specific request (SRQ) and a general request (GRQ)) and atleast one optional proprietary data packet. Then, the receiver mayterminate the negotiation phase by transmitting an SRQ/en(SRQ/end-negotiation) packet. When such a phase is terminated, thetransmitter proceeds to the power transfer phase and the transmitterstops providing the locked slots.

In the power transfer phase, the receiver transmits the CI packet usingthe allocated slot. The, the receiver receives the power. The powerreceiver may include a regulator circuit. The regulator circuit may beincluded in the communications and control unit. The receiver mayself-regulate the reflection impedance of the receiver through theregulator circuit. That is, the receiver may adjust the reflectionimpedance so as to transfer the amount of power required for an externalload and prevent reception of excessive power or overheat. In the sharedmode, the transmitter may not adjust the power corresponding to thereceived CI packet according to the operation mode, so that it ispossible to control preventing an over-voltage situation in this case.

Foreign object detection (FOD) extensions

Hereinafter, FOD extension for detecting a foreign object that is not awireless charging object in performing the powertransmission/reception/control method in the inductive mode describedabove with reference to FIGS. 3 and 4 will be described. This FODextension may be performed in such a manner that the negotiation phase,a calibration phase, and a renegotiation phase are added to a basicsystem control method, as illustrated in FIG. 10. The newly added phasesmay mainly perform a function for detecting the foreign object.

FIG. 10 is a diagram illustrating a method for controlling a wirelesspower transmission/reception system to which FOD extension is appliedaccording to an embodiment of the present invention. The description ofeach phase described above with reference to FIGS. 3 and 4 may beapplied in the same or similar manner and hereinafter, differences fromFIGS. 3 and 4 will be mainly described, and duplicated description willbe omitted.

Referring to FIG. 10, in the selection phase, the power transmitter maymonitor an interface surface and monitor the placement and removal ofobjects using small measurement signals. This measurement signal shouldnot wake up the power receiver located on the interface surface. Whenthe power transmitter senses the foreign object on the interfacesurface, the power transmitter needs to remain in the selection phaseand should not provide the electric power signal to prevent overheatingof the foreign object.

In the negotiation phase, the power receiver may negotiate with thepower transmitter to minutely adjust the power transfer contract. Tothis end, the power receiver may transmit a negotiation request to thepower transmitter which the power transmitter may accept or reject. Inaddition, to improve a capability of an initial evaluation of thepresence of the foreign object, the power transmitter may compare aquality factor reported by the power receiver with a measurement value(or signal) thereof. When the power transmitter detects the foreignobject, the process needs to return to the selection phase.

In the calibration phase, the power transmitter may enhance a capabilityto detect the foreign object during power transmission. In particular,the power transmitter may adjust parameters of a power loss method.Here, the power receiver may provide the reception power thereof undertwo load conditions.

In the power transfer phase, the power transmitter may continually checkwhether a new foreign object is placed on the interface surface. To thisend, the power transmitter may use an FOD power loss method based on,for example, a calibrated power loss calculation. The power receiver mayalso check the placement of the new foreign object. When the powertransmitter or power receiver detects the foreign object, the powertransmitter and/or the power receiver must reduce the electric powersignal or remove the electric power signal and return to the selectionphase.

In the renegotiation phase, the power transmitter may adjust the powertransfer contract when desired. If necessary, the renegotiation phasemay be terminated prematurely without changing the power transfercontract.

In the calibration phase, the power transmitter needs to receive fromthe power receiver information which the power transmitter will use toimprove the power loss method for the FOD. In particular, the powertransmitter needs to receive received power information from the powerreceiver and the power receiver at this time transmits the receivedpower information at a light load (disconnected load) and a connectedload. If the power transmitter does not receive such received powerinformation, the power transmitter may remove the electric power signaland return to the selection phase. However, the power transmitter mayattempt to improve the power loss method by using the received powerinformation only when it is confirmed that there is no foreign object.

The operation of the power transmitter in the calibration phase may bethe same as the operation in the power transfer phase, but the followingoperations may be added.

If the power transmitter receives a 24-bit received power packet withthe mode field set to ‘001’ (calibration mode for the light load) and ifthe received power value is met, the power transmitter may transmit anACK response. Otherwise, the power transmitter may transmit an NAKresponse.

If the power transmitter receives a 24-bit received power packet withthe mode field set to ‘010’ (calibration mode for the connected load)and if the received power value is met, the power transmitter maytransmit the ACK response and continuously perform the power transferphase. Otherwise, the power transmitter may transmit the NAK response.

Here, the received power packet (RPP) may correspond to a packettransmitted to the power transmitter at least once by the power receiverin the negotiation phase in order to change the format of the receivedpower packet determined in the power transfer contract. When the powertransmitter transmits the ACK response to the received power packet, theformat of the received power packet in a provisional power transfercontract may be changed based on the received power packet in which theACK response is transmitted.

Communication article selection method in wireless power transmitter andpower receiver using multi-communication rule

Hereinafter, a communication rule selection method in a wireless powertransmitter and power receiver using a multi-communication rule isdescribed with reference to FIGS. 11 to 13. The following contentsrelate to a communication rule selection method which enables variousapplications of wireless power transmission by supporting variouscommunication methods between a power transmitter and a power receiver.

In order for power transmitters and power receivers manufactured bydifferent companies to smoothly perform their roles, a wireless powertransmission-related technology is standardized in WPC. In a wirelesspower transmission method regulated in WPC, only uni-directionalcommunication from a power receiver to a power transmitter is supportedfor stabilized output control. A major object of the communication is tofeed a control error back from the power receiver to the powertransmitter. An amplitude modulation method using a change in themagnetic field is used as a modulation method, and the transfer rate ismerely several kHz. Accordingly, a communication method regulated so faris vulnerable to an electrical, magnetic disturbance and supports onlyuni-directional communication, and is impossible for applications, suchas the transfer of information from a power transmitter to a powerreceiver. Furthermore, the current communication method has a limit inthe transfer of a large amount of information because the transfer rateis low.

FIGS. 11 and 12 are concept views showing a WPC communication flow.

In the last phase of the communication flowchart of FIG. 11, a phase fordetermining whether to use a different communication method other than acommunication method regulated in WPC may be added as in FIG. 12.Accordingly, the present invention can extend the application range of apower transmitter and power receiver by optionally providing a method ofperforming communication according to a different communication methodin addition to the standards regulated in WPC. A description regardingeach phase of FIGS. 10 and 12 is the same as that of FIGS. 3 and 9, anda redundant description is omitted.

FIG. 13 is a communication flowchart according to an embodiment of thepresent invention.

Referring to FIG. 13, first, a power receiver may transmit, to a powertransmitter, communication information indicating whether a firstcommunication method, that is, a communication method according to theWPC standard, and a second communication method, that is, a differentcommunication method, may be used/supported using the communicationmethod according to the WPC standard (S1310).

In this case, to perform communication using the communication methodaccording to the WPC standard may be interpreted as having the samemeaning as that in-band (IB) communication is performed. To performcommunication using a communication method not complying with the WPCstandard may be interpreted as having the same meaning as thatout-of-band (OOB) communication is performed. IB communication, aspreviously defined in the WPC standard, may be performed based on a loadmodulation method (Rx to Tx) and a frequency shift keying (FSK) method(Tx to Rx).

Next, the power transmitter may determine whether the secondcommunication method may be used using the communication informationreceived from the power receiver (S1320). The second communicationmethod may be various communication methods used for short rangecommunication. For example, the second communication method may be atleast one of Bluetooth, radio frequency identification (RFID), infrareddata association (IrDA), a ultra wideband (UWB), ZigBee, near fieldcommunication (NFC), (wireless-fidelity (Wi-Fi), Wi-Fi Direct orwireless universal serial bus (USB) technology. Specifically, the secondcommunication method may correspond to a Bluetooth communication methodcommonly used in home appliances.

If the power transmitter and the power receiver can use the secondcommunication method, the power transmitter and the power receiver maybe separately equipped with hardware communication modules supportingthe second communication method.

Next, if the second communication method may be used (Yes in S1320), thepower transmitter may notify the power receiver whether the secondcommunication method may be used as a response to the communicationinformation (S1330). A response phase for the communication informationmay be selectively performed and may be omitted or substituted withanother phase.

Next, the power receiver that has received information indicating thatthe second communication method may be used may determine whether to usethe second communication method (S1360). If it is determined thatcommunication will be performed using the second communication method(Yes in S1360), the power receiver may notify the power transmitter thatcommunication will be performed using the second communication method.That is, the power receiver may notify the power transmitter whether touse the second communication method as a response to the reception ofthe information indicating that the second communication method may beused.

Thereafter, if it is determined that the use of the second communicationmethod is possible, the power transmitter may initialize a communicationstate so that communication is performed using the second communicationmethod (S1340). Furthermore, the power receiver may initialize acommunication state in order to use any one of the first and the secondcommunication methods (S1370).

More specifically, if the power receiver uses the second communicationmethod, the communication state of the power receiver may be initializedin order to perform communication using the second communication method(S1380). However, if it is determined that communication is notperformed using the second communication method (No in S1360), the powerreceiver may perform communication using the first communication methodaccording to the WPC standard (S1362).

Although the power transmitter has initialized the communication stateso that communication is performed using the second communicationmethod, if the power receiver performs communication using the firstcommunication method, the power transmitter may also be controlled toperform communication using the second communication method. Morespecifically, if the power receiver does not perform communication usingthe second communication method within a preset time or continues toperform communication using the first communication method, the powertransmitter may change a communication method/state to the firstcommunication method.

If, as a result of the determination of the power transmitter,communication using the second communication method cannot be performed(No in S1320), the power transmitter performs communication with thepower receiver using the existing first communication method regulatedin WPC and may not perform a phase of transmitting informationindicating that communication state initialization and communication arepossible (S1322).

A communication rule selection method according to the presentembodiment has an effect in that the application range of a wirelesscharging system is widened because a new communication rule can beselected between a power transmitter and a power receiver. Moreover, ifa communication rule robust against disturbance is added as acommunication rule that may be selected between a power transmitter anda power receiver, wireless charging performance improvement can beexpected.

Furthermore, the communication rule selection method according to thepresent embodiment may be applied all wireless charging systemsborrowing an induction method and/or a resonance method and wirelesscharging systems in which compatibility between an induction method anda resonance method is possible.

Power class and profile of power transmitter and power receiver

Currently, in WPC, a power class (PC) for a power transmitter and apower receiver is classified as follows based on transmitted andreceived power levels

1. PC 0

-   -   Least guaranteed power is 5 watt (W)    -   Potential guaranteed power (i.e., maximum guaranteed power) is        possible up to 30 W    -   Example of a major application: a smartphone

2. PC 1

-   -   Least guaranteed power is 30 W    -   Potential guaranteed power (i.e., maximum guaranteed power) is        possible up to 150 W    -   Example of a major application: a lap-top, a power tool

3. PC 2

-   -   Least guaranteed power is 200 W    -   Potential guaranteed power (i.e., maximum guaranteed power) is        possible up to 2 kW    -   Example of a major application: Kitchen appliances

As described above, the PC may be identified based on a power level, andwhether to support compatibility between the same PCs may be optional oressential. In this case, compatibility between the same PCs means thatpower transmission and reception are possible between the same PCs. Forexample, if a power transmitter having a PC x can charge a powerreceiver having the same PC x, it may be considered that compatibilitybetween the same PCs is maintained. Likewise, compatibility betweendifferent PCs may also be supported. In this case, compatibility betweendifferent PCs means that power transmission and reception are possiblebetween different PCs. For example, if a power transmitter having a PC xcan charge a power receiver having a PC y, it may be considered thatcompatibility between different PCs is maintained.

As described above, the support of compatibility between PCs is a veryimportant issue in the user experience and infra construction aspect.However, the maintenance of compatibility between PCs has the followingseveral problems technically.

In the case of compatibility between the same PCs, for example, a powerreceiver of a lap-top charging method capable of stable charging onlywhen power is continuously transmitted may have a problem in that it isstably supplied with power from a power transmitter of a power toolmethod that discontinuously transmits power although the powertransmitter is a power transmitter having the same PC. Furthermore, inthe case of compatibility between different PCs, for example, if a powertransmitter having the least guaranteed power of 200 W transmits powerto a power receiver having maximum guaranteed power of 5 W, there is adanger that the power receiver may be damaged due to an overvoltage. Asa result, it is difficult to take the PC as an index/criterion thatrepresents/indicates compatibility.

Accordingly, hereinafter, a ‘profile’ is newly defined as anindex/criterion that represents/indicates compatibility. That is, it maybe construed that stable power transmission and reception are possiblebecause compatibility is maintained between a power transmitter andpower receiver having the same ‘profile’ and power transmission andreception are impossible between a power transmitter and power receiverhaving different ‘profiles.’

FIG. 14 is a table illustrating profiles newly defined according to anembodiment of the present invention.

Referring to FIG. 14, the profile may be defined depending on whethercompatibility is possible and/or an application regardless (orindependently of) a power class.

For example, the profile may be basically divided into four types; i)mobile, ii) power tool, iii) kitchen, and iv) wearable.

In the case of the ‘mobile’ profile, a PC is PC0 and/or PC1, acommunication protocol/method is IB and OOB (optional), an operatingfrequency may be defined as 87˜205 kHz, and examples of an applicationmay include a smartphone and a lap-top.

In the case of the ‘power tool’ profile, a PC is PC1, a communicationprotocol/method is IB, an operating frequency may be defined as 87˜145kHz, and examples of an application may include a power tool.

In the case of the ‘kitchen’ profile, a PC is PC2, a communicationprotocol/method is NFC-based, an operating frequency may be defined asbeing less than 100 kHz, and examples of an application may includekitchen/home appliances.

In the case of the ‘wearable’ profile, a PC is PC-1, a communicationprotocol/method is IB, an operating frequency may be defined as 87˜205kHz, and examples of an application may include a wearable device wornon a user body.

The maintenance of compatibility between the same profiles may beessential, and the maintenance of compatibility between differentprofiles may be optional.

The above-described profiles (mobile profile, power tool profile,kitchen profile and wearable profile) may be generalized and representedas first to n-th profiles. A new profile may be added/substitutedaccording to the WPC standard and embodiments.

If the profiles are defined as described above, more stable powertransmission is possible and a burden of a power transmitter is reducedbecause the power transmitter selectively performs power transmission ononly a power receiver having the same profile as the power transmitter.There is an effect in that a danger of damage to a power receiver isreduced because a power transmitter does not attempt power transmissionto a power receiver incapable of compatibility.

PC1 within the ‘mobile’ profile may be defined by borrowing an optionalextension, such as OOB based on PC0. In the case of the ‘power tool’profile, a PC1 ‘mobile’ profile may be defined a simply changed version.Furthermore, PC1 has been defined to maintain compatibility between thesame profiles so far, but a corresponding technology may be subsequentlydeveloped to maintain compatibility between different profiles.

A power transmitter or receiver may notify a counterpart power receiveror transmitter of its profile through various methods. Thisspecification proposes a method for a power transmitter and powerreceiver to indicate its own profile through a specific field within aspecific packet. Embodiments of a packet defined/configured to indicatea profile are proposed hereinafter. Specifically, there are hereinafterproposed embodiments in which reserved bits within packets defined inthe existing WPC standard are used as a Profile bit/field indicative ofa profile.

FIG. 15 is a diagram illustrating a configuration packet (0x51) of apower receiver according to a first embodiment of the present invention.

Referring to FIG. 15, the configuration packet used by a power receiverin order to notify a power transmitter of its own power receptioncharacteristic/ability may include a Power Class bit/field (2 bits), aProfile bit/field (2 bits), a Maximum Power Value bit/field (6 bits), aProp bit/field (1 bit), a Count bit/field (3 bits), a Window Sizebit/field (5 bits), a Window Offset bit/field (3 bits), a Neg bit/field(1 bit), a Polarity bit/field (1 bit) and/or a Depth bit/field (2 bits).The configuration packet may be transmitted and received in theidentification/configuration (or construction) phase.

The Power Class bit/field indicates a PC of a power receiver.

The Maximum Power Value bit/field may indicate different informationdepending on whether a power receiver supports a foreign objectdetection (FOD) (extension) function. If the power receiver does notsupport the FOD extension function, this bit/field may indicate maximumamount of power (Watt) that the power receiver expects to be receivedfrom the output of a power transmitter/rectifier. If the power receiversupports the FOD extension function, this bit/field may indicate thescaling coefficient of a received power value reported by the powerreceiver through a received power packet. In this case, this bit/fieldmay be configured as a value twice the maximum amount of power (Watt)that the power receiver expects to be provided.

The Prop bit/field may indicate a power transmission control method of apower transmitter, which is desired by a power receiver.

When the Neg bit/field is set to ‘0’, this may indicate that a powertransmitter should not transmit any response. When this bit/field is setto ‘1’, a power transmitter may indicate that a power receiver shouldtransmit an acknowledge (ACK) response after a configuration packetindicating that the power receiver enters the negotiation phase.

When the Polarity bit/field is set to ‘0’, this may indicate that apower transmitter should use a default FSK polarity. When this bit/fieldis set to ‘1’, this may indicate that a power transmitter should use areversed FSK polarity.

The Depth bit/field may indicate an FSK modulation depth.

The Count bit/field may indicate the number of optional configurationpackets transmitted by a power receiver in theidentification/configuration phase.

The Window Size bit/field may indicate an averaged window size ofreceived power in a 4 ms unit.

The Window offset bit/field may indicate a time interval between awindow for averaging received power and received power packettransmission in a 4 ms unit.

The Profile bit/field may indicate profiles (e.g., the above-describedfour different profiles) of a power receiver. For example, the Profilebit/field:

may indicate the mobile profile when it is set as ‘00b’,

may indicate the power tool profile when it is set as ‘01b’

may indicate the kitchen profile when it is set as ‘10b’

may indicate the wearable profile when it is set as ‘11b’

However, the Profile bit/field is not limited thereto, and a bit/fieldvalue indicative of a specific profile may be set as a different value.

FIG. 16 is a diagram illustrating a capability packet (header: 0x31) ofa power transmitter according to a first embodiment of the presentinvention.

Referring to FIG. 16, the capability packet (0x31) used by a powertransmitter to notify a power receiver of its own power transmissioncharacteristic/capability may include a Power Class bit/field (2 bits),a Guaranteed Power Value bit/field (6 bits), a Profile bit/field, aPotential Power Value bit/field (6 bits), a wireless power identifier(WPID) bit/field (1 bit) and/or a Not Res Sens. bit/field (1 bit).

The capability packet may be transmitted and received in the negotiationphase (or re-negotiation phase).

The Power Class bit/field indicates a PC of a power transmitter.

The Guaranteed Power Value bit/field indicates a maximum guaranteedpower value included in a power transfer contract (PTC-GP) that may benegotiated by a power transmitter in a current surrounding condition. Inthis case, the surrounding condition may correspond to a temperature ofthe power transmitter, the amount of power that may be drained by thepower transmitter from a power source shared with other powertransmitters and/or the presence or absence of a foreign object orfriendly metal, for example. The Guaranteed Power Value bit/fieldindicates a power value in a 0.5 W unit.

The Potential Power Value bit/field indicates a maximum guaranteed powervalue included in a power transfer contract (PTC-GP) that may benegotiated by a power transmitter in an ideal surrounding condition.This field also indicates a power value in a 0.5 W unit.

The WPID bit/field indicates that a power transmitter has no ability toreceive a WPID packet.

The Not Res Sens. bit/field may be set as a different value for eachdesign of each power transmitter. In general, this bit/field may be setto a value ‘0’ in order to indicate a power transmitter design capableof frequency control of less than 150 kHz as a power transfer contractincluding a maximum power value greater than 5 W.

The Profile bit/field may indicate profiles (e.g., the above-describedfour different profiles) of a power transmitter. For example, theProfile bit/field:

may indicate the mobile profile when it is set as ‘00b’,

may indicate the power tool profile when it is set as ‘01b’,

may indicate the kitchen profile when it is set as ‘10b’,

may indicate the wearable profile when it is set as ‘11b’.

However, the Profile bit/field is not limited thereto, and a bit/fieldvalue indicative of a specific profile may be set as a different value.

FIG. 17 is a diagram illustrating a configuration packet (0x51) of apower receiver according to a second embodiment of the presentinvention.

The configuration packet according to the second embodiment is the sameas the configuration packet according to the first embodiment exceptthat the size of the Profile bit/field is 3 bits. Accordingly, thedescription of FIG. 15 may be identically applied to this drawing, and aredundant description thereof is omitted.

The Profile bit/field according to the second embodiment

may indicate the mobile profile when it is set as ‘000b’,

may indicate the power tool profile when it is set as ‘001b’,

may indicate the kitchen profile when it is set as ‘010b’,

may indicate the wearable profile when it is set as ‘011b’, for example,and ‘100b-111b’ may be set as reserved bits.

However, the Profile bit/field is not limited thereto, and a bit/fieldvalue indicative of a specific profile may be set as a different value.

FIG. 18 is a diagram illustrating a capability packet (header: 0x31) ofa power transmitter according to a second embodiment of the presentinvention.

The capability packet according to the second embodiment is the same asthe capability packet according to the first embodiment except that thesize of the Profile bit/field is 3 bits. Accordingly, the description ofFIG. 16 may be identically applied to this drawing, and a redundantdescription is omitted.

The Profile bit/field according to the second embodiment:

may indicate the mobile profile when it is set as ‘000b’,

may indicate the power tool profile when it is set as ‘001b’,

may indicate the kitchen profile when it is set as ‘010b’,

may indicate the wearable profile when it is set as ‘011b’, and‘100b-111b’ may be set as reserved bits.

However, the Profile bit/field is not limited thereto, and a bit/fieldvalue indicative of a specific profile may be set as a different value.

FIG. 19 is a diagram illustrating a configuration packet (0x51) of apower receiver according to a third embodiment of the present invention.

The configuration packet according to the third embodiment is the sameas the configuration packet according to the first embodiment exceptthat the size of the Profile bit/field is 4 bits and a profileindication method is different. Accordingly, the description of FIG. 15may be identically applied to this drawing, and a redundant descriptionis omitted.

The Profile bit/field according to the third embodiment may beconfigured with 4 bits, and may indicate a specific profile based on thelocation of a bit value ‘0’ or ‘1’ within the Profile bit/field. Forexample, a specific profile may be indicated based on the location of a‘0’ value (or ‘1’ value) within the Profile bit/field. As a result,unlike in the first and the second embodiments, a plurality of profilesmay be indicated at the same time.

For example, when the ‘0’ value:

is located in the first least significant bit (LSB) (e.g., ‘0000b’)within the Profile bit/field, the Profile bit/field may indicate themobile profile,

is located in the second LSB (e.g., ‘1101b’) within the Profilebit/field, the Profile bit/field may indicate the power tool profile,

is located in the third LSB (e.g., ‘1011b’) within the Profilebit/field, the Profile bit/field may indicate the kitchen profile,

is located in the most significant bit (MSB) (e.g., ‘0111b’) within theProfile bit/field, the Profile bit/field may indicate the wearableprofile.

If this is generalized, the location of the ‘0’ value (or ‘1’ value) inthe Profile bit/field may be interpreted as indicating a specificprofile. Accordingly, if a plurality of ‘0’ values is present within theProfile bit/field, the positions of the ‘0’ values and a plurality ofcorresponding profiles may be indicated. For example, a Profilebit/field in which ‘0110b’ has been set may indicate the wearableprofile and the mobile profile. A Profile bit/field in which 1100b′ isset may indicate the mobile profile and the power tool profile.

However, the Profile bit/field is not limited thereto, and the locationof a bit/field value indicative of a specific profile may be setdifferently from that of the embodiment if bit/field values can bedistinguished.

FIG. 20 is a diagram illustrating a capability packet (header: 0x31) ofa power transmitter according to a third embodiment of the presentinvention.

The configuration packet according to the third embodiment is the sameas the configuration packet according to the first embodiment exceptthat the size of the Profile bit/field is 4 bits and a profileindication method is different. Accordingly, the description of FIG. 15may be identically applied to this drawing, and a redundant descriptionis omitted.

The Profile bit/field according to the third embodiment is configuredwith 4 bits. A specific profile may be indicated based on the locationof a bit value ‘0’ or ‘1’ within the Profile bit/field. As a result,unlike in the first and the second embodiment, a plurality of profilesmay be indicated at the same time.

For example, when the ‘0’ value:

is located in the first least significant bit (LSB) (e.g., ‘0000b’), theProfile bit/field may indicate the mobile profile,

is located in the second LSB (e.g., ‘1101b’) within the Profilebit/field, the Profile bit/field may indicate the power tool profile,

is located in the third LSB (e.g., ‘1011b’) within the Profilebit/field, the Profile bit/field may indicate the kitchen profile,

is located in the most significant bit (MSB) (e.g., ‘0111b’) within theProfile bit/field, the Profile bit/field may indicate the wearableprofile.

If this is generalized, the location of the ‘0’ value in the Profilebit/field may be interpreted as indicating a specific profile.Accordingly, if a plurality of ‘0’ values is present within the Profilebit/field, the positions of the ‘0’ values and a plurality ofcorresponding profiles may be indicated. For example, a Profilebit/field in which ‘0110b’ has been set may indicate the wearableprofile and the mobile profile. A Profile bit/field in which 1100b′ isset may indicate the mobile profile and the power tool profile.

However, the Profile bit/field is not limited thereto, and the locationof a bit/field value indicative of a specific profile may be setdifferently from that of the embodiment if bit/field values can bedistinguished.

Referring back to FIG. 14, the mobile profile (or the first profile)includes both PC0 and PC1. This means that a mobile profile powerreceiver of PC0 is capable of power reception and communication from amobile profile power transmitter of PC1 (i.e., maintain compatibilitybetween PC0 and PC1). However, practically, there is a differencebetween communication protocol/methods that may be supported for eachPC. For example, PC0 may support only IB, and PC1 may support IB and/orOOB. Accordingly, in some cases, communication compatibility between apower transmitter and a power receiver may not be maintained because thepower transmitter and the power receiver support different PCs althoughthey have “the same profile (e.g., the first profile/mobile profile).”

However, since compatibility needs to be maintained between a powertransmitter and power receiver having the same profile as describedabove, there is hereinafter proposed a new communication rule selectionmethod for maintaining communication compatibility between a powertransmitter and power receiver having the same mobile profile regardlessof a supported PC.

For convenience of description, a power transmitter and power receiversupporting PC0 and/or PC1 may be interpreted as meaning a PC0 and/or PC1support power transmitter and power receiver having the same profile(e.g., mobile profile/first profile), although separately mentionedhereinafter.

Communication protocol/method selection method in which profile and/orPC has been taken into consideration

A communication protocol/method basically includes the firstcommunication protocol/method (IB) and the second communicationprotocol/method (OOB), as described above in relation to FIGS. 11 to 13.Both the first and the second communication protocols/methods are takeninto consideration as a communication protocol/method of a powertransmitter now supporting PC1. Which one of the two communicationprotocols/methods is preferred for each essential function (or category)of a power transmitter supporting PC1 is described with reference toFIG. 21.

FIG. 21 is a table illustrating preference for a communicationprotocol/method for each category according to an embodiment of thepresent invention.

Referring to FIG. 21, IB (or close-coupled OOB such as NFC) is preferredin the one-to-one relation (safety control) aspect, IB (or close-coupledOOB such as NFC) is preferred in the compatibility aspect with PC0, OOBis preferred in the regulation issue aspect regarding high powermodulation, OOB is preferred in the load variation (e.g., a motor-drivendevice) aspect, and OOB is preferred in the power factor correction(PFC) and isolation aspect with a power supply channel.

That is, since a communication protocol/method preferred for eachnecessary condition/each category is different as IB or OOB, the twoprotocols/methods are supported, but it may be most efficient tooptionally apply a specific protocol/method based on a surroundingenvironment, a charging mode, a communication protocol/methodsupportable by a power receiver and/or a charging object.

Accordingly, this specification proposes a protocol in which a powertransmitter supporting PC1 supports both IB and OOB, but optionallyperforms a specific protocol/method based on a supported communicationprotocol/method and charging condition of a counterpart power receiver(or power transmitter).

FIG. 22 is a flowchart illustrating a communication protocol/methodselection method of a PCI power transmitter according to an embodimentof the present invention. A description regarding the phases (selectionphase, ping phase, ID/configuration (ID/CONFIG) phase, negotiationphase, calibration phase, power transfer phase and re-negotiation phase)is the same as that described in relation to FIGS. 3 and 10, and aredundant description is omitted.

Referring to FIG. 22, the communication protocol/method selection methodmay be basically divided into the state in which a load has not beenconnected and the state in which a load has been connected. The state inwhich a load has not been connected is classified as a low energy mode.In the state in which a load has been connected, power is supplied tothe load. The low energy mode may correspond to phases from theselection phase to the calibration phase. The state in which power issupplied to a load may correspond to phases from the calibration phaseto the re-negotiation phase.

A PCI power transmitter may perform communication using IB in aprotocol-initial step (i.e., prior to the power transfer phase). Thereason for this is that i) compatibility with a PC0 power receiversupporting only IB is maintained, ii) a one-to-one relation between apower transmitter and a power receiver is guaranteed, iii)electro-magnetic interference (EMI)-related regulations according tohigh power output are not problematic as in PC0 in the low energy state.

A PCI power transmitter may negotiate with a power receiver aboutwhether to select which communication protocol/method in the negotiationphase. More specifically, in the negotiation phase, the PCI powertransmitter may negotiate with the power receiver about a communicationprotocol/method to be used in the power transfer phase.

To this end, the PCI power transmitter may first identify a powerreception characteristic of the power receiver based on a configurationpacket received from the power receiver in the configuration phase. Theconfiguration packet may follow the embodiment of FIG. 23.

FIG. 23 illustrates a configuration packet according to an embodiment ofthe present invention.

In this configuration packet, a description regarding the remainingbit/fields except an OOB bit/field is the same as that described inrelation to FIG. 15.

Referring to FIG. 23, the power receiver may transmit, to the PCI powertransmitter, a configuration packet including the OOB bit/fieldincluding selection/support/indication information of a communicationprotocol/method in the configuration phase. That is, the configurationpacket includes the OOB bit/field indicating that the power receiver maysupport which communication protocol/method (as a communicationprotocol/method to be used during the power transfer phase (or loadconnection)).

For example, the OOB bit/field may be configured with 1 bit.

The OOB bit/field may indicate that a power receiver does not support anOOB communication protocol/method when the OOB bit/field is set as ‘0’b,and

The OOB bit/field may indicate that a power receiver supports an OOBcommunication protocol/method when the OOB bit/field is set as ‘1’b.

However, the OOB bit/field is not limited thereto, and the OOB bit/fieldmay be configured with various bit sizes and may indicate that a powerreceiver may support which one of IB communication and OOBcommunication.

As described above, the configuration packet including the OOB bit/fieldmay additionally include the Profile bit/field described in FIG. 15, 17or 19. In the present embodiment, it has been a prerequisite that apower receiver has the same profile as a power transmitter. Accordingly,the Profile bit/field of the configuration packet may be configured toindicate the same profile as that of the power transmitter.

The power transmitter that has received the configuration packetrecognizes whether the PC of the power receiver is PC0 or PC1 and thatthe power receiver supports which communication protocol/method using apower class field.

Referring back to FIG. 22, as in the example of FIG. 23, the PCI powertransmitter may negotiate with the power receiver about whichcommunication rule will be selected based on the configuration packetreceived from the power receiver.

If the PC of the power receiver is PC0, a communication protocol/methodmay be selected as IB. The reason for this is that the PC0 powerreceiver can support only IB.

On the contrary, if the PC of the power receiver is PC1, any onecommunication protocol/method may be selected based on the configurationpacket. For example, if the configuration packet of the embodiment ofFIG. 23 is received, when the OOB bit/field included in theconfiguration packet indicates the support of OOB, OOB may be selected.If not, IB may be selected.

As described above, various messages/packets for the negotiation of acommunication protocol/method may be transmitted and received between apower transmitter and a power receiver.

What a PCI power receiver can support which communicationprotocol/method may be previously determined by a manufacturer (based onother restrictions related to a power receiver product characteristic,maximum power of a power receiver, a power level, etc.) in amanufacturing step.

If a PCI power receiver can support both IB and OOB, the PCI powerreceiver may select a preferred/desired communication protocol/methodand indicate selection information with respect to a PCI powertransmitter. In this case, the selection information may be indicatedthrough the OOB bit/field of FIG. 23 or may be indicated through packetstransmitted and received in the negotiation phase. If the selectioninformation is indicated through the OOB bit/field of FIG. 23, the OOBbit/field may be interpreted as follows based on a bit value.

When the OOB bit/field is set as ‘0’b, a power receiver does not preferan OOB communication protocol/method (or prefers an IB communicationprotocol/method),

When the OOB bit/field is set as ‘1’b, a power receiver prefers an OOBcommunication protocol/method.

A PCI power receiver may select a preferred/desired proper communicationrule by taking into consideration a surrounding environment (e.g.,temperature), rules, a power reception characteristic of the powerreceiver, a power transmission characteristic of a power transmitter,etc., and may indicate the communication rule with respect to a PCIpower transmitter using the above-described method.

If IB is selected according to the above-described protocol, IBcommunication may be performed from the power transfer phase. If OOB isselected, OOB communication may be performed from the calibration phase.Specifically, in the case of OOB, an OOB configuration may be performedat the early stage of the calibration phase, and may be started from thecalibration phase regardless of a load connection state.

In the embodiments of FIGS. 22 and 23, IB may be substituted with NFC,and is described later in relation to FIG. 24.

FIG. 24 is a flowchart illustrating a communication protocol/methodselection method of a PCI power transmitter according to an embodimentof the present invention.

The embodiment of this drawing is the same as those of FIGS. 22 and 23except that IB, that is, the first communication method, is substitutedwith NFC. Accordingly, the description of FIGS. 22 and 23 is identicallyapplied to this drawing, and a redundant description is omittedhereinafter.

Referring to FIG. 24, prior to a power transfer phase (i.e., if a loadis not connected), NFC communication may be performed between a powertransmitter and a power receiver. More specifically, the NFC reader of aPCI power transmitter may detect the RFID card and tag of a powerreceiver placed on the PCI power transmitter, and may perform NFCcommunication with the power receiver. NFC communication has advantagesin that i) a one-to-one relation and close-coupled communication betweena power transmitter and a power receiver are guaranteed and ii)electro-magnetic interference (EMI)-related regulations according tohigh power output are not problematic as in PC0 in the low energy state.

Meanwhile, in the case of the present embodiment, as described above, ithas been a prerequisite that a power transmitter and a power receiverhave the same profile. If a profile is not separately defined or has adifferent profile, a power receiver may select a communicationprotocol/method based on its charging method, profile and/or powerreception characteristic, and may transmit selection information to apower transmitter. A selection information transmission method is thesame as that described above in relation to FIGS. 22 and 23.

For example, if a power receiver corresponds to a power tool chargingmethod in which discontinuous power supply is permitted, the powerreceiver may select NFC. The reason for this is that power transfer maybe temporarily stopped while NFC communication is performed. Incontrast, if a power receiver corresponds to a lap-top charging methodin which discontinuous power supply is not permitted (i.e., onlycontinuous power supply is permitted), the power receiver may selectOOB. The reason for this is that the simultaneous execution of chargingand communication is guaranteed if OOB communication is performed.

In the case of the communication protocol/method selection method ofFIGS. 11 to 13, the same profile is not a prerequisite, and a powerclass is also not taken into consideration. If the communicationprotocol/method selection method of FIGS. 11 to 13 is actually applied,there is a problem in that communication compatibility between a powertransmitter and a power receiver is not maintained. In contrast, thecommunication protocol/method selection method of FIGS. 22 to 24 haseffects in that communication compatibility is stably maintained and anefficient communication protocol/method can be selected for eachsituation because the communication protocol/method is selected bytaking into consideration a power class between the same profiles.

A detailed embodiment if a Bluetooth (or Bluetooth low energy (BLE)) isselected/applied as OOB is described below.

In FIGS. 22 to 24, Bluetooth (or BLE) may be used/applied as OOBcommunication. If Bluetooth (or BLE) is used as OOB communication, aBluetooth (or BLE) communication technology standardized so far may beapplied to Bluetooth. Specifically, the Bluetooth (or BLE) communicationtechnology may be designed/applied i) to maintain compatibility with aPC0 system and ii) to construct ubiquitous wireless charginginfrastructure by maintaining the provision of a smooth and intuitivecharging environment to mobile products, such as a smartphone, a laptopand a notebook.

FIG. 25 is a diagram illustrating a Bluetooth (or BLE) medium accesscontrol (MAC) packet of a power receiver according to an embodiment ofthe present invention.

In the negotiation phase, a power receiver may transmit its ownBluetooth (or BLE) MAC address (6 bytes) to a power transmitter using IBcommunication. In this case, the Bluetooth (or BLE) MAC address may betransmitted to the power transmitter through a newly defined packet orthe existing packets transmitted and received in the negotiation phase.In this case, the format of the transmitted packet may be the same asthat shown in FIG. 25. However, the format is not limited thereto, and apacket may be defined in various formats as long as it indicates theBluetooth (or BLE) MAC address of a power receiver.

When the power transmitter successfully receives the correspondingpacket without an error, it may transmit acknowledgement (ACK) to thepower receiver as a response thereto.

FIG. 26 illustrates a Bluetooth (or BLE) handover procedure according toan embodiment of the present invention.

After a negotiation phase using IB communication, a power transmitterPTx may establish a Bluetooth (or BLE) connection using a Bluetooth (orBLE) communication protocol/method and the MAC address of a powerreceiver PRx in the calibration phase.

1. To this end, the power transmitter may transmit, to the powerreceiver, a CONNECT_REQ message to request Bluetooth (or BLE) connectionestablishment with the power receiver. In this case, the transmittedCONNECT_REQ message may have included the MAC address of the powertransmitter and all parameters necessary to establish the Bluetooth (orBLE) connection between the power transmitter and the power receiver.

2. If the Bluetooth (or BLE) connection request of the power transmitteris approved, the power receiver may transmit, to the power transmitter,an ACK message as a response to the CONNECT_REQ message. Accordingly,the Bluetooth (or BLE) connection may be established between the powertransmitter and the power receiver. In this case, in an establishedBluetooth (or BLE) profile, service may be configured as‘WPC_service_UUID.’ The power transmitter may be configured and operateas a master (link layer), a central (generic access profile (GAP)) and aclient (generic attribute profile (GATT)), and the power receiver may beconfigured and operate as a slave (link layer), a peripheral (GAP) or aserver (GATT).

3. Next, an authentication procedure may be performed between the powertransmitter and the power receiver. When the authentication procedure issuccessfully completed, the power transmitter and the power receiverperform communication using the Bluetooth (or BLE).

4. When the authentication procedure is completed, the power transmittermay transmit, to the power receiver, a ‘Read Received Power’ message forrequesting received power information of the power receiver.

5. The power receiver may transmit, to the power transmitter, a‘Received Power’ message including the received power information as aresponse to the ‘Read_Received Power’ message.

6. The power transmitter may transmit a ‘Write_Load_ON’ message to thepower receiver. The ‘Write_Load_ON’ message is a command for allowingthe power receiver to connect to a load and to receive power. In thecurrent WPC standard, the time when a load is connected is determined bya power receiver, but is not limited thereto. As in the A4WP standard, apower transmitter may determine the corresponding time using BLE.

7. The power receiver may transmit, to the power transmitter, a‘Received Power’ message including the received power information as aresponse to the ‘Write_Load_ON’ message.

8. The power transmitter may transmit, to the power receiver, a‘Read_CE’ message for requesting a control error value.

9. The power receiver may transmit, to the power transmitter, a ‘CE’message including a control error value as a response to the ‘Read_CE’message.

10. The power transmitter may transmit, to the power receiver, a‘Read_Received Power’ message for requesting the received powerinformation of the power receiver.

11. The power receiver may transmit, to the power transmitter, a‘Received Power’ message including the received power information as aresponse to the ‘Read_Received Power’ message.

The phases 1 to 7 may be performed in the calibration phase, and thephases 8 to 11 may be performed in the power transfer phase.

FIG. 27 is a flowchart illustrating a wireless power transfer method ofa power transmitter according to an embodiment of the present invention.All the above-described embodiments/descriptions may be applied to thisflowchart identically, and a redundant description is omitted.

First, the power transmitter may perform a selection phase of monitoringthe placement and removal of an object for an interface surface of thepower transmitter (S2710). To this end, the power transmitter may use acoil assembly including a primary coil.

Next, the power transmitter may perform digital ping through a firstcommunication protocol by controlling the communication and controlunit, and may perform a ping phase of receiving a response from a powerreceiver (S2720).

Next, the power transmitter may perform an identification/configurationphase of receiving a configuration packet, including configurationinformation of the power receiver, through the first communicationprotocol (S2730). The configuration packet includes information on allthe power reception characteristics of the power receiver. Specifically,the configuration packet may include power class information of thepower receiver and/or communication protocol information of the powerreceiver. The power class information may indicate a power classclassified based on a received power level of the power receiver. Thecommunication protocol information may indicate a communication protocolsupported or preferred by the power receiver.

Next, the power transmitter may perform a negotiation phase of selectingany one of the first communication protocol and a second communicationprotocol different from the first communication protocol based on thepower class information and/or the communication protocol informationthrough the first communication protocol by controlling thecommunication and control unit (S2740). In the negotiation phase, thepower transmitter may identify a power class of the power receiver basedon the power class information. When the power class of the powerreceiver is a power class 0 (i.e., PC0), the first communicationprotocol may be selected. In contrast, when the power class of the powerreceiver is a power class 1 (i.e., PC1), the power transmitter mayselect the first or the second communication protocol based on thecommunication protocol information of the power receiver. Morespecifically, if the communication protocol information indicates thatthe power receiver supports or prefers the second communicationprotocol, the power transmitter may select the second communicationprotocol. If the communication protocol information indicates that thepower receiver does not support or prefer the second communicationprotocol, the power transmitter may select the first communicationprotocol.

The power class of the power receiver may be basically divided into apower class 0 and a power class 1. The power class 0 may indicate thatreceived power of the power receiver is within a 5 W to 30 W range. Thepower class 1 may indicate that received power of the power receiver iswithin a 30 W to 150 W range. Furthermore, the first communicationprotocol may correspond to an IB communication protocol defined in awireless power transmission and reception system. The secondcommunication protocol may correspond to an OOB communication protocoldefined in other communication systems other than a wireless powertransmission and reception system. For example, the TB communicationprotocol may correspond to a communication protocol based on the loadmodulation and FSK method defined in the WPC standard, and the OOBcommunication protocol may correspond to a short range communicationprotocol.

Next, the power transmitter may perform a calibration phase of improvingthe ability to detect an alien substance by controlling a specificparameter (S2750).

Next, the power transmitter may perform communication with the powerreceiver through the selected communication protocol by controlling thecommunication and control unit, and may transfer power to the powerreceiver by controlling the power conversion unit (S2760).

If the second communication protocol is selected in the negotiationphase and the second communication protocol corresponds to Bluetooth,the power transmitter may receive, from the power receiver, theBluetooth MAC address of the power receiver used for Bluetooth in thenegotiation phase. In this case, the power transmitter may transmit, tothe power receiver, a connection request message including the BluetoothMAC address and parameters necessary to establish a Bluetooth connectionin the calibration phase.

Meanwhile, the power transmitter and the power receiver may be assumedor pre-required to have the same profile. The compatibility of powertransfer and communication is maintained between the power transmitterand the power receiver having the same profile. The profile of the powerreceiver may be indicated through a configuration packet. The profile ofthe power transmitter may be indicated through a capability packetincluding information on a power level transferred by the powertransmitter.

The drawings have been separated and described for convenience ofdescription, but the embodiments described with reference to thedrawings may be merged and designed to implement a new embodiment.Furthermore, the present invention is not limitedly applied to theconfigurations and methods of the above-described embodiments, and someof or all the embodiments may be selectively combined so that theembodiments are modified in various ways.

Furthermore, although preferred embodiments have been illustrated anddescribed above, this specification is not limited to theabove-described specific embodiments, and a person having ordinary skillin the art to which this specification pertains may modify thedisclosure in various ways without departing from the gist of thedisclosure in the claims. Such modified embodiments should not beindividually understood from the technical spirit or prospect of thisspecification.

Meanwhile, in this specification, A and/or B may be interpreted asmeaning at least one of A and B.

The present invention may be applied various wireless chargingtechnologies.

What is claimed is:
 1. A method for receiving, by a power receiver,wireless power from a power transmitter, the method comprising: a pingphase of detecting execution of digital ping of the power transmitterand transmitting a response to the detected digital ping to the powertransmitter using a first communication protocol; and a configurationphase of transmitting a configuration packet to the power transmitterusing the first communication protocol, wherein the configuration packetincludes communication protocol information of the power receiverindicating a second communication protocol supported by the powerreceiver; wherein the power receiver supports the second communicationprotocol, based on that a value of the communication protocolinformation is ‘1’, and wherein the power receiver does not support thesecond communication protocol, based on that the value of thecommunication protocol information is ‘0’.
 2. The method of claim 1,wherein the first communication protocol corresponds to an inband (IB)communication protocol defined in a wireless power transmission andreception system, and wherein the second communication protocolcorresponds to an out-of-band (OOB) communication protocol.
 3. Themethod of claim 2, wherein the OOB communication protocol is defined ina different communication system other than the wireless powertransmission and reception system.
 4. The method of claim 2, wherein theIB communication protocol corresponds to a communication protocol basedon a load modulation and frequency shift keying (FSK) method, andwherein the OOB communication protocol corresponds to a short rangecommunication protocol.
 5. The method of claim 1, further comprising: anegotiation phase of selecting any one of the first communicationprotocol and the second communication protocol, wherein the secondcommunication protocol is different from the first communicationprotocol, when the second communication protocol is selected in thenegotiation phase and the second communication protocol corresponds toBluetooth, the negotiation phase further comprises transmitting aBluetooth medium access control (MAC) address of the power receiver usedin the Bluetooth.
 6. The method of claim 1, further comprising: anegotiation phase of selecting any one of the first communicationprotocol and the second communication protocol, wherein the secondcommunication protocol is different from the first communicationprotocol, and a power transfer phase of performing communication withthe power transmitter using the selected communication protocol andreceiving power from the power transmitter, wherein the phase ofselecting the first or the second communication protocol comprises:selecting the second communication protocol, based on that the value ofthe communication protocol information is ‘1’, and selecting the firstcommunication protocol based on that the value of the communicationprotocol information is ‘0’.
 7. A power receiver, comprising: a coilassembly including at least one secondary coil to receive power from aprimary coil of a power transmitter; a power pick-up unit configured toconvert a power signal received through the coil assembly into electricenergy; and a communication and control unit configured to controlcommunication and power transfer with the power transmitter, wherein thecommunication and control unit is configured to: transmit, to the powertransmitter, a response to a digital ping of the power transmitter usinga first communication protocol, and transmit, to the power transmitter,a configuration packet using the first communication protocol, whereinthe configuration packet includes communication protocol information ofthe power receiver indicating a second communication protocol supportedby the power receiver, wherein the power receiver supports the secondcommunication protocol, based on that a value of the communicationprotocol information is ‘1’, and wherein the power receiver does notsupport the second communication protocol, based on that the value ofthe communication protocol information is ‘0’.
 8. The power receiver ofclaim 7, wherein the first communication protocol corresponds to aninband (IB) communication protocol defined in a wireless powertransmission and reception system, and wherein the second communicationprotocol corresponds to an out-of-band (OOB) communication protocol. 9.The power receiver of claim 8, wherein the OOB communication protocol isdefined in a different communication system other than the wirelesspower transmission and reception system.
 10. The power receiver of claim8, wherein the IB communication protocol corresponds to a communicationprotocol based on a load modulation and frequency shift keying (FSK)method, and wherein the OOB communication protocol corresponds to ashort range communication protocol.
 11. The power receiver of claim 7,wherein the communication and control unit is further configured to:select any one of the first communication protocol and the secondcommunication protocol in a negotiation phase, wherein the secondcommunication protocol is different from the first communicationprotocol, and transmit, to the power transmitter, a Bluetooth mediumaccess control (MAC) address of the power receiver used in theBluetooth, based on that the second communication protocol is selectedin the negotiation phase and the second communication protocolcorresponds to Bluetooth.
 12. The power receiver of claim 8, wherein thecommunication and control unit is further configured to: select any oneof the first communication protocol and the second communicationprotocol in a negotiation phase, wherein the second communicationprotocol is different from the first communication protocol, andcommunicate with the power transmitter using the selected communicationprotocol and receive power from the power transmitter in a powertransfer phase, wherein the phase of selecting the first or the secondcommunication protocol comprises: selecting the second communicationprotocol, based on that the value of the communication protocolinformation is ‘1’, and selecting the first communication protocol basedon that the value of the communication protocol information is ‘0’.